iLuveketchup

Anyone know why the sky, what looks like different steps, has different shades? This a pano shot consisting for 16 shots. Each shot has that hard edge light fall off. I was under a lamp post, would the stray light from the post do this? Sorry for the newb ques.

The shot was taken w/ a Sigma 30mm consisting of 16shots. The shot was taken in manual (always) f/16 @ 30secs. I AF on the Empire State building & set the focus on manual thereafter. I started from the left to the right. I have a feeling that the lamp post on my left side caused stray light. Although the lens did have a hood.

The shot is unedited, except for the photomerge.


Here's another pano taken in a different location. This is a 6shot pano taken w/ a 50mm, manual, f/16 @ 30secs. This example shows no hard edge shade fall off.

no_really

it's because each individual shot was metered independenly. This results in the sky being a slightly different shade in every shot.

You need to set your camera on a manual mode, or otherwise lock the exposure setting prior to doing a panorama series. The other, less desireable option is to use photoshop or something to blend the edges together. You can probably successfully blend the edges in the one you already took. It looks good BTW.

F1-Fanatic

I agree... Also, I thought an image that wide would require more than 16 shots.

iLuveketchup

How do you lock the exposure?? (Breaks out the manual as we speak). Oh ok got it. I'll go back tonight & take another shot(s). This time w/ the exposure locked. Thanks!!! I'll post results tonight.

nibble

I agree with above and I would also add fixed ISO rather than auto.

F1-Fanatic

Shoot with your camera in manual mode. Meter for correct exposure and then recompose for your other shots. As long as you are shooting in manual mode and don't touch the ISO, Aperture, or Shutter Speed for all intents and purposes the exposure is locked and will not change

iLuveketchup

[QUOTE=F1-Fanatic,Dec 18 2006, 01:35 PM] Shoot with your camera in manual mode.

Penforhire

Lock the white balance either in-camera or in raw conversion too!

iLuveketchup

White balance is the same in ACR 3.6 on all 16 shots. Here is crop to make it easier to see what I'm talking about. What is that 45 degree line in all the shots? Please don't mind those spots on the photo. I have dust on my sensor. This crop consists of 5.5 shots (you can tell by the dust).

no_really

you know, the problem is probably the lens. Wides commonly have issues with light fall-off as you get to the edges, and the particular way your panoramic scene is put together is probably exaggerating the issue. In many cases, the corners can be a full stop off of the center of the image. Most 50mm lenses don't exhibit any light fall-off at all, which is why your 50mm panoramic looks so smooth.

There's nothing wrong with the particular lens, nor is this problem confined to Sigma. It's just a function of wide angle lenses.